1. Field of the Invention
The present invention relates to a range image generating apparatus, and specifically relates to a range image generating apparatus capable of preventing or reducing generation of range images with interference, which include, e.g., pixels with erroneous distance values.
2. Description of the Related Art
Conventionally, there has been known a range image generating apparatus that generates a range image whose pixel values are distance values, by radiating modulated light from a light source, receiving light reflected by an object and converting the light into charges by means of photoelectric conversion elements, distributing the charges converted by the photoelectric conversion elements into a plurality of charge storage units in synchronization with modulation of the light source, and performing a predetermined calculation based on the charges stored in the plurality of charge storage units (for example, see Japanese Patent Application Laid-Open No. 2004-32682).
However, in this type of range image generating apparatus, the distances are measured by radiating modulated light and obtaining the phase difference between the modulated light and the reflected light. Accordingly, if there is another range image generating apparatus in an imaging range, the range image generating apparatus will directly receive modulated light radiated from that other range image generating apparatus. At that time, if the modulation frequency of the modulated light radiated from the own range image generating apparatus and the modulation frequency of the modulated light radiated from the other range image generating apparatus are the same, the own range image generating apparatus may erroneously detect a phase difference of an incident light containing the modulated light radiated from the light source of the other range image generating apparatus and a reflected light components of the modulated light radiated from the light source of the other range image generating apparatus, resulting in generation of a range image including pixels with erroneous distance values (hereinafter, also referred to as a “range image with interference”).